• Title/Summary/Keyword: pre-mixed

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Effect of the Various Combinations of the Binders and the Silica Fume Types to the Physical Properties of the Pre-Mix Cement (프리믹스 시멘트의 물리적 특성에 미치는 결합재조합 및 실리카퓸 종류의 영향)

  • Jin, Cheng-Ri;Kim, Ki-Hoon;Pei, Chang-Chun;Lee, Hai-III;Kim, Sung-Su;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.11a
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    • pp.37-40
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    • 2007
  • This study investigates the effect of the pre-mix cement to the physical properties of the concrete according to the various combinations of the binders and the silica fume types. The results are summarized as following. For the properties of the fresh, the fluidity in the case that OPC+cilica fume-blast-furnace slag is appropriate compared to OPC+cilica fume+fly ash. Expecially, it is favorable when pre-mix is used. The fluidity time of the A, B depending on silica fume types is favorable, but it is decreased on C. The air content depending on silica fume types is low when the fly ash is used. Specially, the air content in the case that pre-mix is used is low caused by the dispersion of the silica fume. For the properties of the hardened concrete, the compressive and flexible strength when the blast-furnace slag is pre-mixed are high, and they exceed OPC. The strength depending on the silica fume types is high on B, and the strength of the others is similar.

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Design of Echo Classifier Based on Neuro-Fuzzy Algorithm Using Meteorological Radar Data (기상레이더를 이용한 뉴로-퍼지 알고리즘 기반 에코 분류기 설계)

  • Oh, Sung-Kwun;Ko, Jun-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.5
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    • pp.676-682
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    • 2014
  • In this paper, precipitation echo(PRE) and non-precipitaion echo(N-PRE)(including ground echo and clear echo) through weather radar data are identified with the aid of neuro-fuzzy algorithm. The accuracy of the radar information is lowered because meteorological radar data is mixed with the PRE and N-PRE. So this problem is resolved by using RBFNN and judgement module. Structure expression of weather radar data are analyzed in order to classify PRE and N-PRE. Input variables such as Standard deviation of reflectivity(SDZ), Vertical gradient of reflectivity(VGZ), Spin change(SPN), Frequency(FR), cumulation reflectivity during 1 hour(1hDZ), and cumulation reflectivity during 2 hour(2hDZ) are made by using weather radar data and then each characteristic of input variable is analyzed. Input data is built up from the selected input variables among these input variables, which have a critical effect on the classification between PRE and N-PRE. Echo judgment module is developed to do echo classification between PRE and N-PRE by using testing dataset. Polynomial-based radial basis function neural networks(RBFNNs) are used as neuro-fuzzy algorithm, and the proposed neuro-fuzzy echo pattern classifier is designed by combining RBFNN with echo judgement module. Finally, the results of the proposed classifier are compared with both CZ and DZ, as well as QC data, and analyzed from the view point of output performance.

Preparation and Adhesion Characteristics of Binary Blended Waterborne Polyurethane (이성분계 혼합 폴리우레탄 수분산체의 제조 및 접착 특성 연구)

  • Kim, Eun Ji;Park, In Kyu;Park, Jae Hyung
    • Journal of Adhesion and Interface
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    • v.19 no.1
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    • pp.5-12
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    • 2018
  • The purpose of this study is to evaluate the adhesive properties of polyurethane mixed aqueous dispersions by omitting the primer, dealing with the preparation of skins for synthetic leather with excellent adhesion by omitting the pre-treatment process. The two-component mixed polyurethane water dispersion was prepared by synthesizing an ester-based polyurethane resin (PU-T) and a carbonate-based polyurethane resin (PU-C) to obtain the final resin. As a result of measuring the peel strength of the adhesive specimens omitting the pre-treatment agent, it was confirmed that the state adhesive strength (ethylene vinyl acetate (middle): $4.2kg_f/cm$ and rubber (outsole): $4.4kg_f/cm$) there was. This makes it possible to omit the pre-treatment process which has been indispensably used in the shoe manufacturing process, thereby reducing the process time and reducing the amount of volatile organic compounds (VOCs) generated in the pre-treatment product, resulting in environmentally advantageous.

Contents Analysis on the Dwellers' Medical Reports in High-Rise Mixed-Use Apartment (주상복합아파트 거주자의 질병자료에 관한 내용 분석)

  • Choi, Byung-Sook;Kang, In-Ho
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2008.04a
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    • pp.187-192
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    • 2008
  • This purpose of this study is to figure out the inter-relationship between the residence stories in high-rise mixed-use apartments and their residents' disease patterns throughout the dweller's medical reports in high-rise mixed-use apartments. Research basic data are obtained from medical fee request of National Health Insurance Corportion. Data are limited a housing complex to 'A' high-rise mixed-use apartment and a medical treatment time to 3 years(2004-2006). Analysis data of total 346,286 medical records, 43,159 disease records, and 8,999 persons are collected. By analyzing those data, findings are as follows: 1) Women is more medical treatments than men, 40-50 age group is more treated, and the residents of 6-25 stories are more received medical treatments. Diseases of the respiratory system and diseases of the eye and adnexa are relatively treated higher than other diseases. 2) The diseases of the respiratory system, the eye and adnexa, the skin and subcutaneous tissue, the ear and mastoid process), and the asthma have not relation to the high-storied residence through the data of disease records and personal records. But the analysis on the data of children, 7 ages and less, is showed a significant relation. And to conclude, there is no relationship between the residence of high-stories in that apartment and dwellers' disease patterns, but there is a little probable to the relationship in the pre-school child.

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Effects of Mulligan's Mobilization with Movement on Talofibular Interval in Subjects with Chronic Ankle Instability

  • Koh, Eun-Kyung;Jung, Do-Young
    • The Journal of Korean Physical Therapy
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    • v.28 no.5
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    • pp.303-307
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    • 2016
  • Purpose: This study was conducted to determine the effects of Mulligan's mobilization with movement (MWM) on changes in the talofibular interval in the sagittal plane in subjects with chronic ankle instability (CAI). Methods: Sixteen subjects with chronic ankle instability participated in this study. The talofibular intervals were measured from US images, and the weight-bearing lunge test was used to assess dorsiflexion of the ankle joint. Each dependent variable were measured on the both affected side and sound side in three trials in pre- and post-MWM. Dependent variables were examined with a two-way mixed-design analysis of variance (ANOVA). The two factors were side (sound side versus affected side) and intervention (pre- versus post-intervention). For post hoc analysis, paired t-tests were performed to compare the dependent variables. A p<0.05 was considered to indicate significance. Results: Dorsiflexion and talofibular interval differed significantly pre- and post-intervention (p<0.05). Post-hoc analysis revealed that the talofibular interval post-MWM was significantly less than that pre-MWM on the both the affected and sound side (p<0.05). The ankle dorsiflexion in the post-MWM group was significantly greater than that in the pre-MWM group on the affected side and the sound side (p<0.05). Conclusion: The Mulligan's MWM decreased the talofibular interval in subjects with CAI. These findings suggest that the MWM technique can change the position of the talus relative to the fibular in the weight bearing position.

Body Image Dissatisfaction and Self-esteem among Korean Pre- and Early Adolescent Girls and Boys: A Five-year Longitudinal Panel Study (후기 아동기 및 초기 청소년의 신체상불만족과 자존감: 종단적 패널 연구)

  • Park, Woochul
    • Human Ecology Research
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    • v.58 no.2
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    • pp.163-176
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    • 2020
  • Longitudinal studies have shown mixed findings on the association between body image dissatisfaction and self-esteem among adolescents. This study examined the longitudinal, reciprocal influences between body image dissatisfaction and self-esteem among Korean pre- and early adolescents by using nationally representative longitudinal panel data from the Korean Youth Panel Study (KYPS). Analyses based on 2,230 participants indicated that girls' body image dissatisfaction was significantly higher than boys'. The trajectory of body image dissatisfaction increased sharply during pre- and early adolescence, but stabilized afterwards for both boys and girls. Self-esteem deteriorated rapidly initially, but began to recover as adolescent girls and boys matured. Structural equation modeling showed that reciprocal influences between body image dissatisfaction and self-esteem were detected for boys. Body image dissatisfaction among girls predicted self-esteem during the entire period, while the opposite direction from self-esteem to body image dissatisfaction emerged two years later. The present study found that, during pre- and early adolescence, body image dissatisfaction and self-esteem develop in a circular fashion by forming a vicious cycle. Implications for the development of intervention and prevention programs are discussed in consideration of age and gender.

Analysis on Basic Characteristics of Mortar with Pre-Mix Cement (프리믹스 시멘트를 사용한 모르터의 기초적 특성 분석)

  • Jin, Cheng-Ri;Jang, Ki-Hyun;Lee, Chung-Sub;Han, Dong-Yeop;Kim, Ki-Hoon;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.05a
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    • pp.93-97
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    • 2008
  • The study analyzed on each kind of basic characteristics in mortar to prove an effect of pre-mix cement, ultra high strength binder. The results were as follows. in characteristics of not set mortar, fluidity time was the quickest at the time of using POBSA and was more delayed at the time of using Fly Ash than at the time of using Blast Furnace Slag as a binder. Mortar ring flow and flow con flow got smaller as fluidity time got longer, on the contrary to fluidity time. Unit capacity mass was smaller at the time of using Fly Ash than at the time of using Blast Furnace Slag. According to pre-mix, it was difficult to discover a regular tendency. In characteristics of hardening mortar, the 28th day compressive strength was better than thing mixed after measuring separately in pre-mix. According to a binder's kind, Silica Fume B, C was better than Silica Fume A.

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Experimental and numerical analysis of mixed mode I/III fracture of sandstone using three-point bending specimens

  • Li, Yifan;Dong, Shiming;Pavier, Martyn J.
    • Structural Engineering and Mechanics
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    • v.76 no.6
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    • pp.725-736
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    • 2020
  • In this work the mixed mode I/III fracture of sandstone has been studied experimentally and numerically. The experimental work used three-point bending specimens containing pre-existing cracks, machined at various inclination angles so as to achieve varying proportions of mode I to mode III loading. Dimensionless stress intensity factors were calculated using the extended finite element method (XFEM) for and compared with existing results from literature calculated using conventional finite element method. A total of 28 samples were used to conduct the fracture test with 4 specimens for each of 7 different inclination angles. The fracture load and the geometry of the fracture surface were obtained for different mode mixities. Prediction of the fracture loads and the geometry of the fracture surface were made using XFEM coupled with a cohesive zone model (CZM) and showed a good comparison with the experimental results.

Mixed Methods Research on the Intercultural Sensitivity of Summer Program Participants; Comparison of US Participants and Korean Language Partners

  • Soyoung Jeong
    • International Journal of Advanced Culture Technology
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    • v.11 no.4
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    • pp.112-122
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    • 2023
  • This study was conducted as part of a summer Korean language and culture program at a university in Korea, aimed at examining the changes in intercultural sensitivity among American students who participated in the program, as well as the Korean students who served as their language partners. The research utilized a mixed-method approach combining qualitative and quantitative analysis. To derive research findings, pre- and post-program Intercultural Sensitivity Scale surveys were administered to participating students and semi-structured interview data were collected from a randomly selected group of six students. The research findings indicated that among a total of twenty-seven students including both American and Korean students, significant changes in intercultural sensitivity were observed in the domain of Interaction Engagement. Furthermore, fourteen American students showed significant changes in their Interaction Confidence, while the Korean students who participated as language partners did not exhibit significant changes in the five subdomains of intercultural sensitivity.